analyze phase

ANALYZE PHASEANALYZE PHASE

Potential Problem AreaPotential Problem Area Lack of participation from the Lack of participation from the

team membersteam members And inadequate data for making And inadequate data for making

decisions and monitoring the decisions and monitoring the processprocess

Black belts should be prepared to Black belts should be prepared to spend time either researching old spend time either researching old records or collecting new records or collecting new information on the processinformation on the process

Purpose of the Analyze Purpose of the Analyze PhasePhase

Evaluate and reduce the variables, Evaluate and reduce the variables, using graphical analysis and using graphical analysis and hypothesis testinghypothesis testing

Identify the vital few factors in order Identify the vital few factors in order to identify the root cause of the to identify the root cause of the defectsdefects

Help to quantify the performance Help to quantify the performance gap and the benefits of improving the gap and the benefits of improving the processprocess

Analyze Phase ToolsAnalyze Phase Tools Histograms: Bar graph that displays the Histograms: Bar graph that displays the

relative frequency of continuous data relative frequency of continuous data valuesvalues

Box Plots: Basic graphing tool that Box Plots: Basic graphing tool that displays five points that represent the displays five points that represent the centering, spread, and distribution of a centering, spread, and distribution of a set of continuous dataset of continuous data The plot consists of a box, whiskers, and The plot consists of a box, whiskers, and

outliers and shows the maximum value, the outliers and shows the maximum value, the minimum value, the median, the 75th minimum value, the median, the 75th percentile and the 25th percentilepercentile and the 25th percentile

Analyze Phase ToolsAnalyze Phase Tools Dot Plots:Dot Plots:

Simple graphical display of data Simple graphical display of data points of a noncontinuous variable, points of a noncontinuous variable, with each observation represented with each observation represented by a dot placed above a horizontal by a dot placed above a horizontal line marked with a range of valuesline marked with a range of values

Analyze Phase ToolsAnalyze Phase Tools Dot Plots:Dot Plots:

The display is similar to a histogram The display is similar to a histogram ( with a horizontal axis), but the ( with a horizontal axis), but the axis is divided into more classesaxis is divided into more classes

Ideally, each distinct observation Ideally, each distinct observation would have its own plotting positionwould have its own plotting position

Useful for comparing distributionsUseful for comparing distributions

Analyze Phase ToolsAnalyze Phase Tools Interval Plots: Great graphical tool to Interval Plots: Great graphical tool to

compare two factorscompare two factors The graph shows the spread of data around the The graph shows the spread of data around the

means of groups by plotting confidence means of groups by plotting confidence intervalsintervals

A confidence interval for specific statistics gives A confidence interval for specific statistics gives us a range of values around the statistic where us a range of values around the statistic where the true statistic can be expected to be located the true statistic can be expected to be located within a given level of certaintywithin a given level of certainty

The calculation of confidence intervals is based The calculation of confidence intervals is based on the assumption that the variable is normally on the assumption that the variable is normally distributed in the populationdistributed in the population

Analyze Phase ToolsAnalyze Phase Tools Scatter PlotScatter Plot

Shows a correlation between two Shows a correlation between two variables, X and Yvariables, X and Y

Shows a graphical relationship Shows a graphical relationship between the dependent variable and between the dependent variable and the independent factorthe independent factor

But just because there is a But just because there is a relationship does not mean there is relationship does not mean there is causationcausation

Analyze Phase ToolsAnalyze Phase Tools Scatter PlotScatter Plot

Useful for investigating the Useful for investigating the influence of one factor at a time influence of one factor at a time over the output or CTQ you suspect over the output or CTQ you suspect to be vitalto be vital Helps to prove or disprove a hypothesis Helps to prove or disprove a hypothesis

you might have formulated about the you might have formulated about the problemproblem

Analyze Phase ToolsAnalyze Phase Tools Time Series PlotsTime Series Plots

Sequence of measurements, taken at Sequence of measurements, taken at successive points in timesuccessive points in time

Includes a wide range of exploratory and Includes a wide range of exploratory and hypothesis-testing methods that have two hypothesis-testing methods that have two main goals:main goals:

Understand the phenomenon represented by Understand the phenomenon represented by the measurementsthe measurements

Predict future values of the variable tracked in Predict future values of the variable tracked in the time seriesthe time series

Analyze Phase ToolsAnalyze Phase Tools Time Series PlotsTime Series Plots

Most time series patterns can be Most time series patterns can be described in terms of two basic described in terms of two basic categories: trend and seasonalitycategories: trend and seasonality Trend analysis is a time series that Trend analysis is a time series that

showsthe data, the fitted trend line, and showsthe data, the fitted trend line, and forecasts ( linear, quadratic, forecasts ( linear, quadratic, exponential, S-curve)exponential, S-curve)

Seasonality is a time series pattern that Seasonality is a time series pattern that shows a basic repetitive pattern over a shows a basic repetitive pattern over a long period of timelong period of time

Analyze Phase ToolsAnalyze Phase Tools Multivari AnalysisMultivari Analysis

Graphical analysis technique used to identify Graphical analysis technique used to identify and quantify dominant sources of variation in and quantify dominant sources of variation in a process when the Y’s are continuous and a process when the Y’s are continuous and the X’s under investigation are discretethe X’s under investigation are discrete

Data collection is passive in that the process Data collection is passive in that the process is monitored in its natural, unchanged stateis monitored in its natural, unchanged state

Can be used to assess capability, stability, Can be used to assess capability, stability, and graphical relationships between X’s and and graphical relationships between X’s and Y’sY’s

Analyze Phase ToolsAnalyze Phase Tools Multivari studies should continue until Multivari studies should continue until

the full range of the output variable is the full range of the output variable is observed and all treatment observed and all treatment combinations have been capturedcombinations have been captured

If all treatment combinations have been If all treatment combinations have been observed and Y has not varied through observed and Y has not varied through its full range, the X’s are not critical to its full range, the X’s are not critical to YY

Objective: to reduce the large number of Objective: to reduce the large number of possible causes of variation to a smaller possible causes of variation to a smaller family of variationfamily of variation

Analyze Phase ToolsAnalyze Phase Tools Multivari AnalysisMultivari Analysis

Basic steps in multivari analysisBasic steps in multivari analysis Step 1: Call a team meetingStep 1: Call a team meeting Step 2:Select the potential X’s to include in the Step 2:Select the potential X’s to include in the

studystudy Step 3: Establish a sampling planStep 3: Establish a sampling plan Step 4: Plan the method for collecting the dataStep 4: Plan the method for collecting the data Step 5: Collect the dataStep 5: Collect the data Step 6: Analyze the resultsStep 6: Analyze the results

Analyze Phase ToolsAnalyze Phase Tools Hypothesis TestingHypothesis Testing

A null hypothesis (H0) states the A null hypothesis (H0) states the assumption that there is no difference in assumption that there is no difference in parameters for two or more populations, parameters for two or more populations, that any observed difference in samples is that any observed difference in samples is due to chance or a sampling errordue to chance or a sampling error

A null hypothesis is used to check whether the A null hypothesis is used to check whether the new processs mean differs from the old process new processs mean differs from the old process meanmean

The beta risk is the probability of accepting the The beta risk is the probability of accepting the null hypothesis (H0) as true when it is actually null hypothesis (H0) as true when it is actually falsefalse

Analyze Phase ToolsAnalyze Phase Tools Hypothesis TestingHypothesis Testing

An alternate hypothesis ( Ha or H1) An alternate hypothesis ( Ha or H1) is any hypothesis that differs from a is any hypothesis that differs from a given null hypothesisgiven null hypothesis

It states that the observed It states that the observed difference or relationship between difference or relationship between two populations is real, that it is not two populations is real, that it is not the result of chance or a sampling the result of chance or a sampling errorerror

Analyze Phase ToolsAnalyze Phase Tools Analysis of VarianceAnalysis of Variance

Purpose: to test for significant Purpose: to test for significant differences between or among two or differences between or among two or pore means by comparing variances pore means by comparing variances within groups and variances between within groups and variances between and among groupsand among groups

ANOVA used to calculate the amount ANOVA used to calculate the amount of variation in a process and of variation in a process and determine if it is significant or if it is determine if it is significant or if it is caused by random noisecaused by random noise

Analyze Phase ToolsAnalyze Phase Tools Two types of analysis of variance:Two types of analysis of variance:

One’Way ANOVA allows comparison One’Way ANOVA allows comparison of several groups of observations, all of several groups of observations, all of which are independent but of which are independent but possibly with a different mean for possibly with a different mean for each groupeach group

Two-Way ANOVA studies the main Two-Way ANOVA studies the main effects of two factors separately and effects of two factors separately and sometimes together ( the effects of sometimes together ( the effects of their interaction)their interaction)


If a factor is a common cause and it If a factor is a common cause and it contributes significantly to contributes significantly to variability in the output, the team variability in the output, the team has an opportunity to improve the has an opportunity to improve the process by controlling the factorprocess by controlling the factor


If the primary sources of variation If the primary sources of variation are special causes, uncontrollable, are special causes, uncontrollable, and they are significant, the team and they are significant, the team might recommend redesigning the might recommend redesigning the process to withstand that variability process to withstand that variability to the degree possible or that the to the degree possible or that the project be abandonedproject be abandoned

Ascertain and Prioritize the Ascertain and Prioritize the Vital Few Causes of Vital Few Causes of

VariationVariation At this point the team screens At this point the team screens

potential causes for change in the potential causes for change in the target Y and identifies the vital few target Y and identifies the vital few X’sX’s

In most processes there are six or In most processes there are six or fewer factors that most affect the fewer factors that most affect the quality of outputs in that processquality of outputs in that process Whe you isolate these factors you know Whe you isolate these factors you know

what basic adjustments you need to make what basic adjustments you need to make to markedly improve the processto markedly improve the process


VariationVariation To estimate the impact of each X on Y To estimate the impact of each X on Y

and prioritize the causes, the black belt and prioritize the causes, the black belt will develop theories about possible will develop theories about possible causes and the use data to confirm or causes and the use data to confirm or disprove those theoriesdisprove those theories

To verify its findings the team then To verify its findings the team then gathers additional data and might gathers additional data and might conduct experiments on the process, conduct experiments on the process, making certain changes to see if the making certain changes to see if the problems disappearproblems disappear


VariationVariation To determine the key input To determine the key input

variables that cause the target variables that cause the target output variables to vary and then output variables to vary and then to prioritize those inputs, the to prioritize those inputs, the team can use ANOVA, analysis of team can use ANOVA, analysis of means (ANOM), F-test ,t-test, chi means (ANOM), F-test ,t-test, chi square test and/or design of square test and/or design of experimentsexperiments


VariationVariation The team might check its findings The team might check its findings

by using an association matrixby using an association matrix This matrix helps prioritize possible This matrix helps prioritize possible

solutions to develop for the root solutions to develop for the root causes associated with the highest-causes associated with the highest-priority outputspriority outputs

• List the root causes across the top and the List the root causes across the top and the possible solutions down the left sidepossible solutions down the left side

• Then mark in each cell the potential of each Then mark in each cell the potential of each solution to reduce or eliminate the effects of solution to reduce or eliminate the effects of each root causeeach root cause

Transform the Gaps into Transform the Gaps into Improvement ProjectsImprovement Projects

Team members prioritize the Team members prioritize the opportunities to impose the opportunities to impose the processprocess• Which problems should they solve to Which problems should they solve to

achieve the greatest gains?achieve the greatest gains? Then they generate alternatives, Then they generate alternatives,

evaluate those alternatives, and evaluate those alternatives, and select the best solutionsselect the best solutions

Transform the Gaps into Transform the Gaps into Improvement ProjectsImprovement Projects

They identify any potential problems They identify any potential problems and obstacles they might encounter and obstacles they might encounter in implementing those solutionsin implementing those solutions

They decide on the people and the They decide on the people and the resources that will be necessary to resources that will be necessary to improve the processimprove the process

Finally translation of the Finally translation of the improvement opportunity into improvement opportunity into financial termsfinancial terms

Review the Project with the Review the Project with the ChampionChampion

Key Questions:Key Questions: Does the team understand the root Does the team understand the root

causes of the variation and verify causes of the variation and verify them?them?

Are there any significant factors to be Are there any significant factors to be further investigated in the Improve further investigated in the Improve Phase?Phase?

Are the Project and financial Are the Project and financial statements still valid?statements still valid?

Review the Project with the Review the Project with the ChampionChampion

Key Questions:Key Questions: Have the problem and goal statements Have the problem and goal statements

been updated to reflect the additional been updated to reflect the additional knowledge gained from the Analyze knowledge gained from the Analyze phase?phase?

Have any additional benefits been Have any additional benefits been identified that will result from closing identified that will result from closing all or most of the gaps?all or most of the gaps?

Conduct an Analyze Conduct an Analyze Phase- Gate Review Phase- Gate Review

analyze phase

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